1. Field of the Invention
This invention relates to a monitor control system which is installed in a plant or the like where an object to-be-monitored such as a substation exists, and in which the alarm events of faults etc. having occurred in the object to-be-monitored are displayed on an HMI (Human Machine Interface).
2. Description of the Related Art
A prior-art monitor control system having been extensively used is such that, when the alarm event of a fault or the like occurs in an object to-be-monitored, the object to-be-monitored transmits the alarm event to an HMI, and that the HMI retains the name and event occurrence time of the received alarm event in a list form and permits an operator to confirm the contents thereof on an event list screen.
Also, there has been extensively used a system wherein an alarm level is set every alarm event beforehand, and upon receiving the alarm event, the HMI affixes the set alarm level to the name and occurrence time of the alarm event and then retains them in the list form.
Besides, there has been a monitor system wherein events having occurred in the object to-be-monitored are handled as the alarm events, only in a certain predetermined time zone, and the alarm events are suppressed in any other time zone, whereby the object to-be-monitored can be monitored only on the necessary occasion. In, for example, a system stated in Patent Document 1 (JP-A-63-52298, pages 2-4 and FIG. 1), the mask data of individual time zones are prepared for each of a plurality of monitor point sensors beforehand, and when the monitor point sensor operates, the mask data is selected in accordance with the time of the operation, so as to decide if the operation of the monitor point sensor is regarded as the alarm event, in accordance with the selected mask data, whereby at the operation of each monitor point sensor, the alarm event is generated only in the certain time zone.
In the prior-art monitor control system, the alarm level is set every alarm event beforehand. Therefore, even the alarm event whose degree of importance changes depending upon time zones, for example, a “door open” event which signifies that the door of the plant to-be-monitored has opened, is handled as the same alarm level in all the time zones. This has posed the problem that the alarm event which is essentially unnecessary is displayed.
Besides, in the system as stated in Patent Document 1, wherein the event having occurred in the object to-be-monitored is handled as the alarm event, only in the certain time zone, and the alarm event is suppressed in any other time zone, the alarm event itself is not generated during the suppression. Accordingly, there has been the problem that, although the object to-be-monitored has fallen into a state where an alarm is to be generated, this fact does not remain in a record at all.